This invention relates to lead-acid cells and to sealed lead-acid cells, and, more particularly, to a seismic rated racking system for housing such cells.
Stationary batteries are specifically designed for float applications, that is, as standby power in the event of a power failure. Stationary batteries are usually maintained at a full-state-of-charge and in a ready-to-use condition typically by floating at a constant preset voltage. Standby batteries are used for standby or operational power in the communications field, utilities, for emergency lighting in commercial buildings and uninterruptible power supplies.
Uninterruptible power supplies are systems that back-up computers and communication networks. Sealed lead-acid cells and/or batteries may comprise the power source. The uninterruptible power source allows for the orderly shut down of computers when there is a sudden interruption in the primary electrical source, such as during a power outage and provides back-up power for communications networks. The uninterruptible power supply also will accommodate short, or intermittent, losses in power. When there is a power interruption, the batteries in the uninterruptible power system can be subject to rapid discharge.
The sealed lead-acid stationary cells and/or batteries used for industrial applications where the power requirements are high and quite demanding are typically comprised of from several to a large number of individual sealed lead-acid cells connected to one another to form a battery with the desired capacity and power requirements. The individual sealed lead-acid cells may be connected in series, in parallel or in suitable combinations of series and parallel to form a battery with the desired capacity and power requirements. External connections are typically made between the negative and positive terminal posts of the respective cells.
Because of space considerations, these large capacity cells need to be placed on racks, cabinets or the like in an attempt to minimize the space requirements. A complicating factor in designing suitable cabinets and cell tray assemblies is that, for Universal Building Code Zone IV applications, i.e., locations where high seismic conditions can occur, there are stringent requirements that must be met to ensure that the cells are adequately secured in the racks should such high seismic conditions occur. Indeed, from a manufacturing and inventory control standpoint, a cell tray assembly is desirable which can be used in all applications, rather than requiring a design unique for Zone 4 applications.
The wiring in previous seismically rated racking systems typically extends out beyond the envelope of the rack. Thus, additional space beyond the footprint of the rack is required to allow for wiring. Additionally, previous systems can be difficult to assemble in that they comprise a large number of loose parts which must be assembled together leading to increased assembly and handling costs.
In addition to the above considerations, it is necessary to provide a cost-effective cell tray assembly that satisfies the varying, and demanding, criteria as discussed herein while overcoming the disadvantages likewise discussed herein. None of the cell racks and assemblies currently available satisfies such objectives.
It is accordingly a principal object of the present invention to provide a cost effective battery racking system which is easy to assemble and is seismically rated to satisfy UBC Zone IV requirements.
Another object of the invention is to provide a battery racking system that is entirely contained within the rack footprint, not requiring additional footprint space merely for the attachment of external couplers or wiring.
A further object is to provide a cell tray assembly for housing cells used for stand-by applications in which each cell is retained in the assembly, yet is readily accessible from the front of the assembly.
Yet another object of the present invention provides a battery racking system which is inexpensive, may be readily manufactured, and is easy to utilize in the field.
These and other objects and advantages of the present invention will be apparent upon the following description and drawings. It should be appreciated that the intention is not to limit the present invention to the disclosed embodiments, but, rather, the intention is to cover all embodiments within the scope of the present invention as disclosed and claimed hereinafter. While the present invention has been described primarily in conjunction with an open rack, the present invention is equally applicable to other types of cabinets or the like.
The invention provides a racking system which includes a frame supporting shelves on which battery cells are disposed. Channels extending along the outsides of the shelves allow the placement of wires within the footprint of the racking system. Restraints for maintaining the cells in position during seismic activity are coupled to the frame.